Large is hard to specify, as it depends on what hardware you have supporting your site, how much traffic you get, etcetera. To use thevbgeek.com as an example,
GAL
works okay with the current traffic, hardware, and stats:

Code:

Threads: 3,392, Posts: 20,799, Members: 3,992

The current
GAL
6 release is from the
GAL
5 code. Before The Geek left, he was working on a different
GAL
6 that was to be better optimized. There is a thread about it and its possible release here but currently I do not have a copy of that code and cannot tell you if/when I'd get a copy or if/when a new
GAL
release would be made.

GAL

The Geek Auto-linker is the famous vBulletin system for auto highlighting key words is posts with links and/or popups.

A wonder for glossaries and sponsors!

__________________Please use the forums for support, feature requests, and similar such things. Support does not include custom code, custom template edits, or third-party modifications. PMs and emails to me should be for private information only, such as login information. If you PM or email me a support question, chances are good that I'll ignore it. Thanks. While the work or play is on, it is a lot of fun if while you are doing one you don't constantly feel that you ought to be doing the other. -- Franklin Pierce Adams

Hopefully someone with a larger board, who has updated from v.4.8 to v.6.0 can give you some feedback. I started with the
GAL
5 code base and haven't looked at the
GAL
4 code base to see what extra weight was added. My guess is that rebuilding post cache could be a problem so if I were you, I'd consider waiting until/if/when I get a copy of The Geek's
GAL
6 but it may take a looong time, assuming I get a copy, before a new release is available.

GAL

The Geek Auto-linker is the famous vBulletin system for auto highlighting key words is posts with links and/or popups.

A wonder for glossaries and sponsors!

__________________Please use the forums for support, feature requests, and similar such things. Support does not include custom code, custom template edits, or third-party modifications. PMs and emails to me should be for private information only, such as login information. If you PM or email me a support question, chances are good that I'll ignore it. Thanks. While the work or play is on, it is a lot of fun if while you are doing one you don't constantly feel that you ought to be doing the other. -- Franklin Pierce Adams

I've used to run (about 2-2.5 year ago)
GAL
for a few weeks on our board and at that time there was a considerable slowdown (thus I removed it). Unfortunately I don't have any experience with the new code bases...

Members: 140,147
Threads: 123,894
Posts: 1,318,346

GAL

The Geek Auto-linker is the famous vBulletin system for auto highlighting key words is posts with links and/or popups.

here's a thought...why not create a version of
GAL
which puts the actual BBCode for links into the posts after the "edit" time expires for users to edit their posts? this way there will be no extra queries at all. it's a static link and not actually querying during each post view.

GAL

The Geek Auto-linker is the famous vBulletin system for auto highlighting key words is posts with links and/or popups.